> For the complete documentation index, see [llms.txt](https://docs.getblock.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.getblock.io/api-reference/optimism-op/optimism_eth_gettransactionbyblocknumberandindex.md).

# eth\_getTransactionByBlockNumberAndIndex - Optimism

This method retrieves a specific transaction from a block by combining the block number with the transaction's index position. This is commonly used to iterate through transactions in a block or to access transactions at specific positions. You can use block tags like `'latest'` as well.

## Parameters

| Parameter        | Type          | Description                                                    | Required |
| ---------------- | ------------- | -------------------------------------------------------------- | -------- |
| blockNumber      | QUANTITY\|TAG | Block number in hex, or `'latest'`, `'earliest'`, `'pending'`. | Yes      |
| transactionIndex | QUANTITY      | The transaction index position in hexadecimal.                 | Yes      |

## Request Sample

{% tabs %}
{% tab title="curl" %}

```bash
curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "eth_getTransactionByBlockNumberAndIndex",
    "params": ["0x7A69B2C", "0x0"],
    "id": "getblock.io"
}'
```

{% endtab %}

{% tab title="Javascript(Axios)" %}
{% code overflow="wrap" %}

```bash
const axios = require('axios');

const url = "https://go.getblock.io/<ACCESS-TOKEN>/";
const headers = { "Content-Type": "application/json" };

const payload = {
    jsonrpc: "2.0",
    method: "eth_getTransactionByBlockNumberAndIndex",
    params: ["0x7A69B2C", "0x0"],
    id: "getblock.io"
};

axios.post(url, payload, { headers })
    .then(response => {
        if (response.status === 200) {
            console.log("eth_getTransactionByBlockNumberAndIndex result:", response.data.result);
        } else {
            console.error("Error:", response.status, response.statusText);
        }
    })
    .catch(error => {
        console.error("Error:", error.response ? error.response.data : error.message);
    });
```

{% endcode %}
{% endtab %}

{% tab title="Python(Request)" %}
{% code overflow="wrap" %}

```py
import requests
import json

url = "https://go.getblock.io/<ACCESS-TOKEN>/"
headers = {
    "Content-Type": "application/json"
}
payload = {
    "jsonrpc": "2.0",
    "method": "eth_getTransactionByBlockNumberAndIndex",
    "params": ["0x7A69B2C", "0x0"],
    "id": "getblock.io"
}

response = requests.post(url, headers=headers, data=json.dumps(payload))

if response.status_code == 200:
    result = response.json().get("result")
    print("eth_getTransactionByBlockNumberAndIndex result:", result)
else:
    print("Error:", response.status_code, response.text)
```

{% endcode %}
{% endtab %}

{% tab title="Rust" %}
{% code overflow="wrap" %}

```rs
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = reqwest::Client::builder()
        .build()?;

    let mut headers = reqwest::header::HeaderMap::new();
    headers.insert("Content-Type", "application/json".parse()?);

    let data = r#"{
    "jsonrpc": "2.0",
    "method": "eth_getTransactionByBlockNumberAndIndex",
    "params": ["0x7A69B2C", "0x0"],
    "id": "getblock.io"
}"#;

    let json: serde_json::Value = serde_json::from_str(&data)?;

    let request = client.request(reqwest::Method::POST, "https://go.getblock.us/<ACCESS_TOKEN>")
        .headers(headers)
        .json(&json);

    let response = request.send().await?;
    let body = response.text().await?;

    println!("{}", body);

    Ok(())
}
```

{% endcode %}
{% endtab %}
{% endtabs %}

## Response

A successful response returns the following:

{% code overflow="wrap" %}

```json
{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "blockHash": "0x1ff2fcd80ed93d75855364f7e879795dbd5790210c5224ad2c1083d9744297d6",
        "blockNumber": "0x7a69b2c",
        "blockTimestamp": "0x67411011",
        "from": "0xdeaddeaddeaddeaddeaddeaddeaddeaddead0001",
        "gas": "0xf4240",
        "gasPrice": "0x0",
        "hash": "0x4fae8f6c70a4f50cf8894bf9847ed364922826658c3cb73e291e03934637a853",
        "input": "0x440a5e200000146b000f79c500000000000000040000000067410f83000000000144320300000000000000000000000000000000000000000000000000000002fe2cca3c00000000000000000000000000000000000000000000000000000000001f11bf37aac56bf514562b0ee38600119c0a4f70b20f0c6abc66a2011d1bdd9b18cb1c0000000000000000000000006887246668a3b87f54deb3b94ba47a6f63f32985",
        "nonce": "0x160d8b6",
        "to": "0x4200000000000000000000000000000000000015",
        "transactionIndex": "0x0",
        "value": "0x0",
        "type": "0x7e",
        "v": "0x0",
        "r": "0x0",
        "s": "0x0",
        "sourceHash": "0xf14ecb423df1f95f609d9781126cdd9ea4d248f4502c083507b2f1f72aa779a8",
        "mint": "0x0",
        "depositReceiptVersion": "0x1"
    }
}

```

{% endcode %}

## Response Parameters

* **`id`**: A unique request identifier, matching the `id` sent in the request body.
* **`jsonrpc`**: Specifies the use of JSON-RPC version 2.0.
* **`result`**: A transaction object with all transaction details, or null if not found.

## Use Case

The eth\_getTransactionByBlockNumberAndIndex method is commonly used for:

* **Transaction iteration**
* **Block processing**
* **Sequential access patterns**

#### Error handling

| Status Code | Error Message    | Cause                                                                                                                                                                      |
| ----------- | ---------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 404         | Not Found        | Missing or invalid ACCESS\_TOKEN.                                                                                                                                          |
| -32602      | Invalid argument | <ul><li>The block number does not exist or is beyond the chain height</li><li>Index is not a valid hex integer</li><li>Block does have transaction at that index</li></ul> |

#### Integration with Web3

The `eth_getTransactionByBlockNumberAndIndex` method helps developers:

* Build trustless UIs that load transaction lists directly from RPC
* Power dashboards analyzing block activity and congestion
* Support exchanges, wallets, and bridges that track transaction placement
* Generate block-level historical analytics
* Verify transaction ordering for MEV, priority fees, and gas bidding strategies

{% tabs %}
{% tab title="Ethers.js" %}

```javascript
import { ethers } from "ethers";
const RPC_URL = "https://go.getblock.us/<ACCESS_TOKEN>";
const provider = new ethers.JsonRpcProvider(RPC_URL);
async function Call() {
  try {
     const result = await provider.send( "eth_getTransactionByBlockNumberAndIndex",
 ["latest", "0x0"]);    
console.log("The result:", result);
    return result;
  } catch (error) {
    console.error("The error:", error);
    throw error;
  }
}
```

{% endtab %}

{% tab title="Viem" %}

```jsx
import { createPublicClient, http } from 'viem';
import { optimism } from 'viem/chains';

// Create Viem client with GetBlock
const client = createPublicClient({
  chain: optimism,
  transport: http('https://go.getblock.us/<ACCESS_TOKEN>'),
});

// Using the method through Viem
async function Call() {
    try {
        // Method-specific Viem implementation
        const result = await client.request({
         method: "eth_getTransactionByBlockNumberAndIndex",
         params: ["latest", "0x0"]
        });
        console.log('Result:', result);
        return result;
    } catch (error) {
        console.error('Viem Error:', error);
        throw error;
    }
}

```

{% endtab %}
{% endtabs %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.getblock.io/api-reference/optimism-op/optimism_eth_gettransactionbyblocknumberandindex.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.